"Changed radio transmission frequency to comply with federal and state spectrum management regulations"

Along with this cryptic change, is a new achievement, titled "Transmission Received", which Shacker ghost in my shell reported unlocking after he "put the radio on the red button on the first stage." At this point it "started spitting out Morse code."

We're still unsure what is actually going on here, but mysterious things appear to be afoot. At the very least, I'd recommend getting this achievement.

Steam users have begun finding images hidden in the updated game files. All of these images clearly show the Aperture Science logo from the game.

I've reached out to Valve Software for comment and I'll keep you updated of any new information.

Update: The following is reportedly a sound made by an in-game radio when thrown into a force field: "Dinosaur_Fizzle" noise Warning: Loud!.

Update 2: Steam users have found 26 new sound files containing around 17 minutes of Morse code. The first file has been translated to read: "interior transmission active external data line active message digest active". Something big is going on.

Update 3: In-game video of some of the Morse code and the above "Dinosaur_Fizzle" noise. Additionally, check these two videos of the near 18-minutes of sounds: Part 1 - Part 2

I got the first 1/26 for the achievement transmission received by taking the very first radio to the first room on the very first level. I get nothing but Morse code now. I assume there are 26 radios to be found.

I know I'm late on this but I just heard a weird sound when I took the radio through that dematerializer wall thingy.